ioctl_fat(2)

💅 ioctl_fat — the manipulating the FAT filesystem era

okay bestie, so this one lives in the System Calls Manual, section 2 — it's ioctl_fat(2), and no cap it's the girl that lets you poke at FAT filesystem metadata you literally cannot reach any other way. 🍓

✨ NAME ✨

ioctl_fat — manipulating the FAT filesystem 💾

📚 LIBRARY 📚

Standard C library (libc, -lc) — she's built right in, you don't gotta install anything.

🫶 SYNOPSIS 🫶

#include <sys/ioctl.h>

int ioctl(int fd, unsigned long op, ...);

🌸 DESCRIPTION 🌸

so the ioctl(2) system call is the main character here, and the way that it works is: you can use it to read and write metadata of FAT filesystems that are genuinely not accessible using other system calls. like, those other syscalls simply cannot, they're not invited. 🙈

The following op values are available, and yes we're listing all of them, no skipping:

🎀 Reading and setting file attributes 🎀

• FAT_IOCTL_GET_ATTRIBUTES(2const)
• FAT_IOCTL_SET_ATTRIBUTES(2const)

🔥 Reading the volume ID 🔥

• FAT_IOCTL_GET_VOLUME_ID(2const)

🦋 Reading short filenames of a directory 🦋

• VFAT_IOCTL_READDIR_BOTH(2const)
• VFAT_IOCTL_READDIR_SHORT(2const)

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⭐ RETURN VALUE ⭐

• On success, a nonnegative value is returned. slay. ✨
• On error, -1 is returned, and errno is set to indicate the error. she'll tell you what went wrong, just read the receipt.

💀 ERRORS 💀

• ENOTTY — the file descriptor fd does not refer to an object in a FAT filesystem. it's giving "wrong girl, wrong filesystem" 😭

👑 STANDARDS 👑

Linux. periodt. 💅

🧚 SEE ALSO 🧚

• ioctl(2)

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okay that's the whole page bestie, you ate, go read some FAT metadata responsibly 💜

this was ioctl_fat(2) from Linux man-pages 6.20, dated 2025-05-17 — mwah, sending you the biggest hug, bye pookie 🫶✨